Application of crosslinked chitosan in the analysis of butyl tin speciation

A new method for the separation and preconcentration of butyl tin speciation with crosslinked chitosan (CCTS) and for its determination by hydride generation atomic absorption spectrometry was developed. At pHs 6.8, 4.4, and 3.0, monobutyl tin (MBT), dibutyl tin (DBT), and tributyl tin (TBT), respectively, were separated and preconcentrated with CCTS, eluted quantitatively with 10 mL of 1 mol L^?1 HCl, and determined. The method was applied to the discrimination and determination of MBT, DBT, and TBT in water and sediment samples. The detection limits of TBT, DBT, and MBT were 21.2, 25.5, and 28.5 ng L^?1, respectively. The analytical recoveries of MBT, DBT, and TBT added to the samples were 91–95% for water samples and 82–90% for sediment samples. The results were satisfactory. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1326–1328, 2004     

三味檀香散无机元素的初级形态分析

采用离子色谱法对三味檀香散中的锂、钠、钾、镁和钙5种元素进行了初级形态分析。结果显示,原药中5种元素的含量顺序为Ca>K>Mg>Na>Li,K总提取率超过了95%,其次Mg为44.93%,其他元素均在25%以下。在各元素残留率中,头煎残留率最高的是Na为90.34%,其次是Ca为80.19%。而颗粒吸附率最高的是K为16.65%。本实验数据为三味檀香散中的无机元素含量与药效关系提供了参考依据。     

无机高分子复合絮凝剂PFSS中硅的形态分析

应用Si-Mo逐时络合比色形态表征法, 对无机高分子复合絮凝剂聚硅硫酸铁（PFSS）中硅的形态进行了研究,包括SiO₂反应速率特征及其标准工作曲线,不同pH值条件下聚硅酸（PSi）的形态分布特征,不同pH值时PFSS与PSi中硅的形态特征比较。结果表明：不同pH值的PFSS中,硅的聚合形态熟化一定时间后,分布规律有所不同。pH值为1.46和1.70时,PFSS中硅酸的中聚体含量比pH值为0.64时的高,而pH值为0.64时,PFSS中硅酸的高聚态、凝胶态含量明显高于pH值为1.46和1.70的相应含量。同时,pH值为1.46和1.70的PFSS比pH值为0.64的PFSS有更好的絮凝性能和稳定性。由此可知,PFSS中聚硅酸的优势形态是其中聚体。     

Polyphenylalanine ionic liquid for the extraction and determination of Allura red in food samples

Poly amino acids ionic liquid {3-(3-(7-(diethylamino)-2-carbonyl-2 h-amino-3-propyl)-1-ethyl Bromo imidazole P[Phe][EMI]} was synthesized and characterized with Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (¹H-NMR), and scanning electron microscopy (SEM). A novel method based on solid-phase extraction and high-performance liquid chromatography for the detection of Allura red (AR) was established. Under optimized conditions, the linear range of AR was 0.01–10.00 μg ml⁻¹, the limit of detection (LOD) was 0.004 μg ml⁻¹ and the enrichment factor was 12.5 (volume of solution/volume of elution). The isothermal adsorption, kinetic model, and Gaussian calculation model was explained by the adsorption mechanism of AR on P[Phe][EMI]. The method was applied to the analysis of real samples with recoveries of 92.0%–102.2% and relative standard deviations of 1.0%–4.6%.     

国内无机晶须在高分子复合材料中的应用研究进展

无机晶须作为一种单晶纤维材料,具有结构完整、强度高、热稳定性好等优点,是塑料、金属和陶瓷等材料的新型改性添加剂,已制成了多种耐热、耐磨、耐腐蚀等高性能材料,应用在机械、电子、汽车等领域。本文综述了硫酸镁、钛酸钾、硼酸铝、硫酸钙、氧化锌和碳酸钙等常用无机晶须的特性及其在高分子复合材料中的应用研究进展。     

A new method for analysis of sunset yellow in food samples based on cloud point extraction prior to spectrophotometric determination

A simple new micelle mediated preconcentration method was developed for analysis of sunset yellow (SY) prior to its spectrophotometric determination. The method was based upon cloud point extraction of the ion associate of SY and trioctylamine (TOA) in HCl–Triton X-100. In the surfactant phase the SY species react with TOA yielding hydrophobic ion associate of SY^?·TOA⁺. The distribution coefficient of SY between surfactant-rich phase and aqueous phase was approximately 104. Validation was tested by comparing the results with standard HPLC. Isotherm and thermodynamic parameters, chemical equilibrium, extraction constants and stiochiometry of the associate were assigned.     

A novel organic gas steam-liquid extraction method for the selective extraction of cobalt from water samples

In this work, for the first time, organic gas steam-liquid extraction (OGS-LE) technique was developed as a promotion in the liquid–liquid extraction (LLE) method, by the use of a special homemade extraction cell that was designed to facilitate the traditional LLE method, without emulsification and with high extraction efficiency by a small amount of organic solvent in one step. This method is fast, simple and efficient, and was employed for the selective extraction and determination of cobalt (II) from water samples. The efficiency of the OGS-LE method was compared with the LLE method. The obtained results revealed that by using the OGS-LE technique, the extraction efficiency of cobalt from a synthetic mixture was over 90%, much higher than the traditional LLE method (34%).     

A new modified multiwalled carbon nanotube paste electrode for quantification of tin in fruit juice and bottled water samples

In this paper, a new modified multiwalled carbon nanotube electrode is reported for anodic stripping voltammetry quantification of tin. The electrode is based on the use of N-Nitrozo-N-Phenylhydroxylamine (cupferron) and multiwalled carbon nanotube. The influence of supporting electrolytes, deposition time, and applied potential on the sensitivity of electrode were investigated. The detection limit was 0.12 ng/ml and the RSD at a concentration level of 50 ng/ml, was 1.5%. The electrode has been applied for the determination of tin in fruit juice and bottled water with the satisfactory results.     

驱油用石油磺酸盐中无机盐含量分析新方法——梯度索氏浸提法

根据"相似相溶"原理,采用梯度索氏浸提法定量分析了石油磺酸盐工业品中无机盐含量。主要讨论了梯度浸提所需溶剂种类和用量、溶剂对各组分浸提效果、以及各组分浸提完全时所需浸提时间和循环次数,并与直接滴定法和SY/T6424-2000行业标准方法进行了比较。实验结果表明,应按照极性递增顺序选用系列有机溶剂在其沸点对石油磺酸盐进行索式浸提;未磺化油经2次浸提后总回收率可达100%;石油磺酸盐经4次浸提后总回收率可达99.86%,无机盐不被有机溶剂浸提,回收率100%。溶剂用量应确保提取管中样品被浸没。分析时间取决于样品用量,约6~7 h可浸提完全。无机盐含量分析结果小于上述2种方法,无机盐纯净,准确度高。该方法具有操作简单、不需昂贵的分析试剂和仪器、溶剂可重复回收利用等优点。     

亚临界水萃取技术及其在有效成分提取和分析领域中的应用

综述了亚临界水萃取技术在有效成分提取和分析领域的研究现状,主要介绍了亚临界水萃取技术在挥发油、黄酮、多糖和蛋白质等天然植物有效成分提取及分析检测等领域的应用,并概述了超声波、微波、酶法等技术与亚临界水萃取联用,最后展望了亚临界水萃取技术的未来发展方向,为该技术的推广及实际应用提供参考。     

亚临界水萃取技术及其在有效成分提取和分析领域中的应用

综述了亚临界水萃取技术在有效成分提取和分析领域的研究现状,主要介绍了亚临界水萃取技术在挥发油、黄酮、多糖和蛋白质等天然植物有效成分提取及分析检测等领域的应用,并概述了超声波、微波、酶法等技术与亚临界水萃取联用,最后展望了亚临界水萃取技术的未来发展方向,为该技术的推广及实际应用提供参考。     

浊点萃取分光光度法测定水样中痕量铁

建立了浊点萃取-分光光度法测定痕量铁的新方法。详细考察了溶液的pH值、螯合剂和表面活性剂浓度、平衡温度和时间等条件对浊点萃取效果的影响。该方法的线性范围为6.0~500μg/L(r=0.9996),检出限为1.58μg/L,加标回收率为98.7%~101.6%,相对标准偏差为1.3%~2.2%。该方法已成功应用于实际水样分析。     

煤矿用高水无机膨胀充填材料泌水分析表征

通过化学方法检测分析了榆阳煤矿高水无机充填材料的泌水组分,分析确定硫酸根离子的浓度为1344mg／L;红外分析发现,溶液中含有机物量少,且都是对人体无害的水泥添加剂组分;原子吸收光谱检测钙、镁离子、硅酸根浓度,其中硅酸根和钙离子超出了仪器的检测范围,即〉1000mg／L,Mg2＋含量为362mg／L。综合检测分析发现,充填泌水主要为高水充填材料中的石膏、水泥、粉煤灰、水泥外加剂等可溶成分。     

Cellulose acetate-iron oxide nanocomposites for trace detection of fluorene from water samples by solid-phase extraction technique

In this study, cellulose acetate (CA)/iron oxide nanocomposites (NC1 and NC2) were synthesized and utilized as extractors for the selective separation of fluorene from aqueous samples. The selectivity of nanocomposites to different organic compounds was assessed. Based on the results, fluorene was the most quantitatively adsorbed on NC2. Batch method was performed by varying the initial fluorene concentrations and contact time. Langmuir and Freundlich isotherms were used for modeling the experimental data and were best correlated by the Langmuir model. Adsorption data were also followed the pseudo-second-order kinetic model. Finally, validation of the developed method was achieved for fluorene determination in real water samples.     

Application of crosslinked carboxymethyl konjac glucomannan in speciation of dissolved Fe(II) and Fe(III) in water samples

A new solid‐phase extraction technique has been developed for the speciation of trace dissolved Fe(II) and Fe(III) in environmental water samples with a microcolumn packed with crosslinked carboxymethyl konjac glucomannan (CCMKGM) prior to its determination by flame atomic absorption spectrometry (FAAS). Various influencing factors on the separation and preconcentration of Fe(II) and Fe(III), such as the acidity of the aqueous solution, sample flow rate and volume, and eluent concentration and volume, have been investigated systematically and optimized. Fe(III) could be quantitatively retained by CCMKGM in the pH range of 3.0–7.0, then the retained Fe(III) on the CCMKGM was eluted with 5.0 mol L^?1 HCl after cleaning with 0.01 mol L^?1 HCl to eliminate Fe(II) and determined by FAAS. Total Fe was determined after the oxidation of Fe(II) to Fe(III) by H₂O₂, and Fe(II) concentration was calculated by subtracting Fe(III) from total iron. The adsorption capacity of CCMKGM for Fe(III) was found to be as high as 162.3 mg g^?1. The detection limit (3σ) for Fe(III) was 1.5 μg L^?1 and the RSD was 3.5% (n = 11, c = 20 μg L^?1) with an enrichment factor of 50. The proposed method has been applied to the speciation of iron in water samples with satisfactory results. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

水中无机砷检测技术的进展

无机砷包括As(Ⅲ)和As(Ⅴ),同有机砷相比,在水中能引发极高的毒性。无机砷检测方法为世界范围内无机砷污染的地区提供了及时有效的检测手段。介绍了分光光度技术、电感耦合等离子体技术、中子活化分析、电化学方法、生物传感技术等检测方法,并介绍了不同技术的组合,适合不同的需要。     

Comparison of BEA, USY and ZSM-5 for the quantitative extraction of polycyclic aromatic hydrocarbons from water samples

The physicochemical properties of three commercial zeolites - namely BEA, USY and ZSM-5 - are compared for the water removal of 15 PAHs included in the US EPA priority pollutants list. The best percentages of extraction were obtained with BEA and varied from 85.2 ± 1.7% (benzo[g,h,i]perylene) to 99.6 ± 1.1% (pyrene). The correlation of physicochemical properties to the percentages of extraction suggests that the predominant factor for a successful extracting performance is the adsorption of PAHs to the external surface of the extracting material. This process is facilitated by relatively large total pore volumes, large average pore diameters and a homogeneous distribution of Lewis acid sites. The presence of the latter enhances extraction performance via π-electron interactions with the aromatic rings of the PAH.     

亚临界水萃取技术在天然产物提取中的研究进展

较详细地介绍了亚临界水萃取技术的原理、设备、工艺流程、影响萃取效果的因素、在天然产物领域的应用及研究成果.指出了该技术存在的问题,并对其应用与发展前景进行了探讨.     

Synthesis and characterization of polymeric inorganic coagulants for water treatment

This research explored the feasibility of preparing and utilizing preformed polymeric solution of Al(III) and Fe(III) as coagulants for water treatment. The differentiation and quantification of hydrolytic Al and Fe species in the coagulants were done by utilizing spectrophotometric method based on the interaction of Al or Fe with ferron as a complexing agent. In addition, 27A1-NMR, FT-IR, and powdered XRD were used to characterize the nature and structure of the hydrolytic species in these coagulants. The properties of the polyaluminum chloride (PAC1) and polymeric iron chloride (PIG) showed that the mass fractions of the maximum polymeric Al produced at r(OH/Al)=2.2 and Fe at r=1.5(OH/Fe) were 85% and 20% of the total aluminum and iron in solution, respectively. Coagulation tests were conducted under various coagulant dosages and pHs for each coagulant prepared. In case of PAC1 coagulants, a coagulation test on Nakdong river waters with three PACls (r=2.0, 2.2, 2.35) showed that the effectiveness of coagulation was in the order, r=2.2>2.0>2.35, corresponding to the order of polymeric aluminum contents. And, for the PIC1 coagulants, the PIC1 of r=1.5 was most effective for the removal of turbidity and TOC from the raw water. Presented at the Int’l Symp. on Chem. Eng. (Cheju, Feb. 8–10, 2001), dedicated to Prof. H. S. Chun on the occasion of his retirement from Korea University.     

Combination of ACO-artificial neural network method for modeling of manganese and cobalt extraction onto nanometer SiO2 from water samples

In this study, modeling based on ant-colony optimization – artificial neural network have been employed to develop the model for simulation and optimization of nanometer SiO₂ for the extraction of manganese and cobalt from water samples. The pH, time, amount of SiO₂ nanoparticles and concentration of 1-(2-pyridylazo)-2-naphthol (PAN) were the input variables, while the extraction% of analytes was the output. Under the optimum conditions, the detection limits were 0.52 and 0.7 μg L^?1, for manganese and cobalt, respectively. The method was applied to the extraction of manganese and cobalt from water samples and one certified reference material.